There's been some recent interest in the Telnet server sketch I created a couple years back. The Telnet server allows all Arduino control pins to be read or written using a simple command line protocol. Once you've loaded the sketch, you should be able to Telnet into the Arduino's IP address, get a prompt, and type ? <cr> for help.

The code on the old forum was developed in Arduino environment 0.23 and no longer compiles without edits. I'm posting the updated code here: http://dl.dropbox.com/u/47320696/ArduinoTelnetServer.zip.